Process for preparing thioketones



"Patented Feb. 20,1945 I I 2,313,647

UNITED STATES PATENT jQFFl--E- PROCESS FOR PREPARING TH IO KETQNESLeslie G. S. Brooker and Grafto H i ester, NrY., assignors to East h ,1I v pany, Rochester, N. Y., a corporation ofNew" y i Name-wing;jAPDlicationMarch 11,1942, w SerialNo. 434,216; 1 t

soleim s; (01. 260- 3041 I This invention relates to aprocess forprepar- Dlgro rp. .Miii'e ing thioketones which are useful asintermediatesv specifically canvlfe li $1 an ealkyl grown; such in thepreparation of carbocyanine and meroas methyl,ethvl',;isoamyl,lfi-ethgiiyethyl, benzyl carhocyanine dyes. or allylforxam-nlahoran .ar l upie s h as,

Thioketones ofthezfollowing: general formula; 5 phenyl, Rf can.represent an alkyl group suoh i asthose given above underR,or;an.iaryl-groun, ch-asph n nh hy io f 1. for e ample 2 T7 p, iThefollowing examples willserve to illustrate v our invention. q Ebttwn' ze15-'chloro 3 ethZlLZJhiopz-opibriylwherein D represents phenylene ornaphthylene, mthylcn'e enzoselenazoline Q representssulfur'orvseleniuintand R and R v I .s'i; each represents an organicradical, are highly H P 3 useful materials for the preparation ofquaterv '2 Geog-( 1:3 nary salts of the general formula: I 0'1 Q5 D ocna y-sit I 1 6' I 6.15; ;g.' l y 'noli); of,-5w-chloror3eethyle2-pro 1. 7 e 1 f 2 piony nethylenebenzoslenazoline,-v4.4.g.i(1moi) Ofph 'OSPhQlTQIJS penta'sulfide and cc. ofpyridine wherein D, Q, and?? have the values given were refluxed";together .;for ten fminutes. The above and R"- represents an alkyl groupand. X reen sh s ut on obtain W poured out intorepresents an acidradical; which. quaternary 5 l1- 1 a l Pt' -z f d salts are, in turn,valuable intermediates forthe tickr as ttwas .p ifiedia b ve t a twnwlth.

synthesis of carbocyanine andmerocarbocyanine 0in 0.7 0 a -s ztg. ofyellow-01 5's: .5

dyes; v H K 1il.M- -;P- 165-167? was obtained. The yield n a iwt v ?S ales-i 56? 16% I 656=and '356,657,-'each filedisepterlnber 13, 19fl0; i I:1 We ha des ribes the i ptra n ,O11f1 Qht iQ- sm g fi fgfifi mt l fketor'iesby thetreatnie of halogenovinylderiYa- I I fthi a id n z siilld'e rthi J r ci-i'a" sulfates. W-hile each-of these methods is'satis- I61 g i factory, each involves the use ofa halogenovinyl 5 I derivativewhich mustlbe ofbtained from the cori 4 responding oxoketone. We havenow found that f the aforesaid thioketones can be prepared directly 2 ty from the oxoketones without going through the 4 4 t I i g. (1 mol.) of2-acetylmethylene-3-ethylt rme a e halogenovinyl' stage 40ibenzothiazoline, 4.4g (1' mol.) of phosphorous it is,- I accordingly; anobject of our invention :to

Pmvide an impmved Pmcesfl Preparing fcrte'nminutesl :Thi gave dirty,dark greenthiol zetones. Qtherobjectswill'becoznejapparent ish 'solutionwhich was poured out into-115d cc;

hereinafte 1i ofwater. A black"solidsenarated whioli'was poi;

In accordance; with' -ou r j invention, we prepare I 5 lectedand"waslied'with water; "Thisp rfoduct'was" I our thioketones bytreatingthe corresponding puiiifiea byixtraicfiofiwithuligfgmxgqelzoo)oxoketones with phosphorous"pentasulfide. Ad-

Y "1*" "16; e vantageously, thepro'c'essis'carried out in a pywe d was g(10%) M P 142 144 ridine medium. The oxoketones which we ema d al???rthiqlle fqlll ll -6- I ploy in practicing our invention can berepree e naphthothiazolme I sented by the following generalformula: v s

2 q=c1i =5 iHs wiiei'emiiresieeenteetnenyieiie a naphthvlene ;-.t,-; t.group i grepresentssulfur'or selenium and R and 3.3 g. (1 mol.) of2-benzoylniethylen'e-- 1eth$jl R ea'ciif represents anorga-nic radicalone end of Q fi-naphthothiazoline,v2.2 g;"(1'mol.') of phosphoronepentasulfide and cc. of pyridine were heated together at refluxingtemperature for fifteen minutes. The reaction mixture was then pouredout into 150 cc. of water. The solid which separated was collected on afilter. It was purified by stirring up with 200 cc. of boiling methylalcohol after which it was collected ona filter and dried, A yield of3.3 g. (94%) was obtained. A small portion was recrystallized frommethyl alcohol and obtained as brownish crystals. M. P. 205-207 dec.

In a manner similar to that illustrated in the foregoing examples,1-ethyl-2thioacetylmethylene-p-naphthothiazoline can be prepared from 2-acetylmethylene-1-ethyl-fi-naphthothiazoline, 3- e t h yl-2-thioacetylmethylene-u-naphthothiazm line can be prepared from2acetylmethylene-3- ethyl-anaphthothiazoline and 3pheny1-2thioacetylmethylene benzothiazoline from2-acetylmethylene-3-phenylbenzothiazoline. 2-a c e t ylmethylene-S-phenylbenzothiazoline can be prepared by treating2-methylbenzothiazole pheniodide with acetyl chloride, in pyridine inaccordance with the process of United States Patent 2,112,139, datedMarch 22, 1938. The Z-methylbenzothiazole pheniodide can be prepared byoxidizing thioacetyldiphenylamine with iodine (see the copendingapplication of Leslie G. S. Brooker and Homer W. J. Cressman, Serial No.353,502, filed August 21, 1940, now U. S. Patent 2,317,357, dated April27, 1943). Also 2-thioace'tylmethylene-3,4-trimethylenebenzolthiazolinecan be prepared from 2acetylmethylehe-ISA-trimethylenebenzothiazoline.2-acetylmethylene- 3,4-trimethylenebenzothiazoline can be prepared bytreating 2methyl-3,4-trimethylenebenzothiazolium iodide with acetylchloride in pyridine in accordance with the process set forth in UnitedStates Patent 2,112,139, dated March 22, 1938. TheZ-methyl-3,4-trimethylenebenzothiazolium iodide can be prepared asdescribed in the aforesaid Brooker and Cressman copending application.

What we claim as our invention and desire to 'be secured by LettersPatent of the United States is:

1. A process for preparing a thioketone comprising treating a compoundof the following general formula:

' selenium radicals, R and R' each represents a member selected from thegroup consisting of alkyl and aryl groups with phosphorous pentasulfide.

2. A process for preparinga thioketone comprising treating a compound ofthe following genwherein D represents a phenylene group and R and R eachrepresents an alkyl group, with phosphorous pentasulfide.

3. A process for preparing a thioketone comprising treating a compoundof the following general formula:

wherein D represents a naphthylene group and R and R' each represents analkyl group, with phosphorous pentasulflde.

4. A process for preparing a thioketone comprising treating acompound-of the following general formula:

e l t wherein D represents a phenylene group and R and R each representsan alkyl group, with phos phorous pentasulfide.

5. A process for preparing a thioketone'comprising treating, in apyridine medium, a compound of the following general formula:

wherein D represents a phenylene group and R and R each represents analkyl group, with phosphorous pentasulfide.

6. A process for preparing a thioketone comprising treating, in apyridine medium, a compound of the following general formula:

S I E wherein D represents a naphthylene group and R and R eachrepresents an alkyl group, with phosphorous pentasulfide.

7..A process for preparing a thioketone comprising treating, in apyridine medium, a compound of the following general formula:

t n V wherein D represents a divalent organic radical selected from thegroup consisting of phenylene and naphthylene radicals, Q represents anatom selected from the group consisting of sulfur and selenium radicals,R and R each represents a member selected from the group consisting ofalgycrll and aryl groups with phosphorous pentasul- LESLIE G. S.BROOKER.

GRAFTON H. KEYES.

